The invention relates to an intake-pipe assembly for internal combustion engines of the type including four to six cylinders arranged in line, or the like. More specifically, the invention relates to such an intake assembly which includes an intake manifold and a plurality of intake pipes opening into the intake manifold at one end thereof and into engine inlet channel means at the opposite ends thereof. Particularly preferred embodiments of the invention relate to arrangements with an intake manifold having intake pipes extending symmetrically therefrom at opposite sides thereof, with the intake pipes being of substantially similar lengths and extending from a connection plane at the intake manifold to a connection plane at the engine inlet channel means extending transversely to said connection plane at the intake manifold.
In a known intake-pipe assembly of this design (U.S. Pat. No. 2,862,490), for a six-cylinder engine with three carburetors, the two immediately adjacent central connecting ends are associated with first individual intake pipes, which extend from the intake manifold at the maximum distance from the connecting ends. Connecting ends which are disposed in a line with the connecting ends, outward on both sides of the above-mentioned connecting ends, are associated with the individual intake pipes, said pipes being adjacent to the first and extending from the intake manifold closer to the connecting ends, while third individual intake pipes, which are adjacent to the second and extend from the intake manifold immediately adjacent to the connecting ends, effect a transition to the outermost connecting ends. The individual intake pipes of this intake pipe assembly consist essentially of straight and diagonal segments, connected together by curves with small radii of curvature. In this design, the flow of gas or mixtures is disturbed in the individual intake tubes by turbulence, so that especially favorable torque and power cannot be achieved over the entire speed range of the engine. Furthermore, the individual intake pipes are relatively short, resulting in additional disadvantages related to torque and power.
A goal of the invention is to provide an intake pipe arrangement of the type described hereinabove, the individual intake pipes of said system having sufficiently great lengths and relatively large radii of curvature without significantly increasing the space requirements of the intake-pipe assembly.
The above-noted goal of the invention is accomplished according to particularly preferred embodiments of the invention by providing that the intermediate segments overlap one another and extend in respective intermediate segment planes, said intermediate segment planes being angularly inclined with respect to one another and intersected with one another in the vicinity of a common intersection area for said intermediate and connecting end segments.
By virtue of the design of the intake-pipe assembly according to the invention, a good vibrational behavior in the individual intake pipes and hence a good torque and power curve for the engine is achieved with very low space requirements for the intake-pipe assembly. The intake-pipe assembly according to the invention is suitable in particular for fuel-injected internal combustion engines of the Otto and Diesel types, and also for Otto engines with carburetors. By swiveling the intermediate cross sections with the intake manifold around the imaginary intersecting axes and relative to the connecting ends whose paths can be adjusted, an overall design of an intake-pipe assembly can be selected which will have the maximum suitability for specific space requirements according to particularly preferred embodiments of the invention.
Advantageous embodiments and features of the invention are characterized in the detailed description of the drawings and in the claims, said claims containing in particular features for a design of the intake-pipe assembly which is favorable for operation and easily cast and contains the casting core for its manufacture. Independent protection has been claimed for these features.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.